28609997 has 8 divisors (see below), whose sum is σ = 32623416. Its totient is φ = 24855552.

The previous prime is 28609961. The next prime is 28610003. The reversal of 28609997 is 79990682.

It can be written as a sum of positive squares in 4 ways, for example, as 11062276 + 17547721 = 3326^2 + 4189^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28609997 - 2¹⁰ = 28608973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28609957) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64508 + ... + 64949.

It is an arithmetic number, because the mean of its divisors is an integer number (4077927).

Almost surely, 2^28609997 is an apocalyptic number.

It is an amenable number.

28609997 is a deficient number, since it is larger than the sum of its proper divisors (4013419).

28609997 is a wasteful number, since it uses less digits than its factorization.

28609997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129487.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 28609997 is about 5348.8313676915. The cubic root of 28609997 is about 305.8482060015.

The spelling of 28609997 in words is "twenty-eight million, six hundred nine thousand, nine hundred ninety-seven".